The present invention relates packages for the packaging of bone-in meat products. More particularly, the present invention relates to a bag having a protective patch adhered directly thereto, the protective patch preventing, or reducing the likelihood, of a bone puncturing completely through the bag and patch thereover.
Heat-shrinkable thermoplastics are known to be useful as flexible packaging materials for vacuum packaging various foodstuffs, including meat. Such plastic materials, however, while generally suitable for packaging meat, understandably have difficulties in successfully packaging sharp or bony products. For example, attempts to package bone-in primal cuts of meat usually result in an unsatisfactorily large number of bag failures due to bone punctures. The use of cushioning materials such as paper, paper laminates, wax impregnated cloth, and various types of plastic inserts have proved to be less than totally satisfactory in solving the problem. The preparation of special cuts of meat or close bone trim with removal of protruding bones has also been attempted. However, this is at best only a limited solution to the problem since it does not offer the positive protection necessary for a wide variety of commercial bone-in types of meat. Furthermore, removal of the bone is a relatively expensive and time-consuming procedure.
The use of heat-shrinkable bags having one or two patches adhered thereto has recently become a commercially-preferred manner of packaging bone-in meat product. However, even the bags having two patches thereon leave xe2x80x9cuncovered regionsxe2x80x9d which are more vulnerable to bone puncture because they do not have a patch adhered thereover.
It has been found that in the packaging of certain bone-in meat products, for example with a patch bag containing a pair of bone-in pork loins, the bones puncture the bag at its one or more xe2x80x9cuncovered regionsxe2x80x9d, i.e., regions of the bag which are not covered by the patch, also herein referred to as xe2x80x9cbald regionsxe2x80x9d. An undesirable level of bone punctures occur even when these uncovered regions have an unshrunken-width of only about 1 inch wide on a bag having an unshrunken, lay-flat width of from about 13 to 17 inches, i.e., a portion of a patch-bag which is about 92% to 94% covered with the patch.
Reorientation of the patch 90xc2x0 relative to the bottom seam of the bag, this reorientation relocating the uncovered regions relative to the bone-in pork loins within the bag, failed to cure the problem of an undesirable level of bone punctures through the uncovered region, due to the fact that the bone-in pork loins have many different points at which exposed bone ends contact the inside surface of the bag. Reorientation 45xc2x0 relative to the bottom of the bag also failed to cure the problem, as bones from at least two different regions resulted in an undesirable level of bone punctures in the relocated uncovered regions.
Providing a much-oversized bag can be used to reduce the number of punctures, as the pork loins can be placed in the center of the bag so that the uncovered regions are present on xe2x80x9cdog-earsxe2x80x9d emanating from the package. However, this solution to the problem is not entirely satisfactory, for several reasons. First, there is the inefficiency of wasted package due to the excessive bag size required to keep the uncovered areas away from the bone-in pork loins. Second, the dog-ears running the length of the package provide an aesthetically less-attractive package. Third, the loins must be carefully placed in the center of the bag, to avoid bone contact with the uncovered areas. Fourth, the meat has the potential to slide around inside the oversized bag, resulting in the potential for the bone to contact uncovered regions, thus increasing the potential for package failure.
It would be desirable to have a patch bag in which the patches leave substantially less total uncovered region, or even substantially no uncovered regions, in order to reduce or eliminate the number of bone punctures.
However, making a patch bag in which the patch extends to the lay flat edge of the bag, or even past the lay-flat edge of the bag, requires that the patch be aligned with the bag. Patch misalignment on the bag can result from patch-lateral mis-alignment, patch-longitudinal misalignment, and patch-skewing. Failure to accurately align the patches with the bag results in exposed glue surfaces which produce difficulties in laminating, bagmaking, and material handling. More particularly, the exposed glue surfaces result in transfer of adhesive to processing rolls, and pickup of dirt and contaminants by the exposed glue, resulting in a requirement of more careful handling. Furthermore, the exposed glue has the potential to cause the wound-up product to adhere to itself. The exposed glue also presents a potential for product contamination. The problems associated with exposed glue surfaces are exacerbated by the fact that the tubing from which the bag is formed has variations in its width, requiring that the patches be of a size to ensure that the entire width of the bag is covered by the patches.
The present invention provides a patch bag in which patches are adhered to both the bag as well as to one another, to provide puncture-resistance throughout a region extending around substantially the entirety of the patch bag. The patch bag of the present invention can reduce the number of punctures at uncovered regions, especially for the packaging of bone-in meat products such as bone-in pork loins.
As a first aspect, the present invention pertains to a patch bag, comprising a bag having a patch adhered thereto, the patch having a first-patch-overhang-region and a second-patch-overhang-region, wherein at least a portion of the first-patch-overhang-region is adhered to the second-patch-overhang-region. Preferably, the first-patch-overhang-region is present on a first patch, and the second-patch-overhang-region is present on a second patch.
As a second aspect, the present invention pertains to a patch bag comprising a patch film adhered to a bag film, wherein: (a) the patch bag comprises at least two seals made through both the patch film and the bag film; (b) the patch film has a thickness of from about 2 to 8 mils, preferably 3 to 5 mils, the patch film comprising ethylene/alpha-olefin copolymer having a density of from about 0.85 to 0.95; and (c) the bag film has a thickness of from about 1.5 to 5 mils (preferably, about 2.5 mils), comprising an O2 barrier layer (preferably comprising at least one member selected from the group consisting of ethylene/vinyl alcohol copolymer, and a composition comprising polyvinylidene chloride wherein the copolymer comprises at least one member selected from the group consisting of methyl acrylate and vinyl chloride) and another layer comprising ethylene/alpha-olefin copolymer having a density of from about 0.85 to 0.95.
Preferably, the patch film comprises at least one member selected from the group consisting of LLDPE, HDPE, VLDPE, ULDPE, homogeneous ethylene/alpha-olefin copolymer, and EVA; more preferably, ethylene/alpha-olefin copolymer having a density of from about 0.91 to 0.93; still more preferably, a composition comprising a blend of 85 to 100 weight percent LLDPE and 0-15 weight percent ethylene/vinyl acetate copolymer, having a vinyl acetate content of about 9 percent.
Preferably, the bag film comprises at least one member selected from the group consisting of LLDPE, HDPE, VLDPE, ULDPE, homogeneous ethylene/alpha-olefin copolymer, EVA, and ethylene/butyl acrylate copolymer (xe2x80x9cEBAxe2x80x9d); more preferably, ethylene/alpha-olefin copolymer having a density of from about 0.91 to 0.93; still more preferably, a composition comprising a blend of 85 to 100 weight percent LLDPE and 0-15 weight percent ethylene/vinyl acetate copolymer, having a vinyl acetate content of about 9 percent.
As a third aspect, the present invention pertains to a packaged product, comprising: (a) a package comprising a patch bag having a patch adhered thereto, the patch having a first-patch-overhang-region and a second-patch-overhang-region, wherein at least a portion of the first-patch-overhang-region is adhered to the second-patch-overhang-region; and (b) a meat product in the package, the meat product comprising bone. Preferably, the first-patch-overhang region is present on a first patch, and the second-patch overhang region is present on a second patch.
The manufacture of patch bags having patches overhanging the bag is not completely free of the above-described problems associated with patch bags having the patch extending to the edge of the bag. More particularly, since overhanging patches are preferably applied one at a time, with adhesive applied to the entirety of that side of the patch which is to be adhered to the tubing later to be sealed and cut to form the bag, one side of the overhanging region of the patch has exposed adhesive thereon, the exposed adhesive building up on rolls, conveyors, etc., upstream of the laminating site. Furthermore, since the tubing having one overhanging patch is rolled up and run through the process again for the application of the second patch on the other side of the lay-flat tubing, courses of the rolled up tubing, having patches adhered to one side thereof, have an opportunity to adhere to themselves, i.e., different courses of this rolled-up xe2x80x9cintermediate productxe2x80x9d have the potential to adhere to one another, as a result of the exposed adhesive on the overhanging patch regions.
Furthermore, the exposed adhesive on the first patches thereafter builds up on rolls downstream of the laminating site, and exposed adhesive due to any misalignment of the two patches can build up on equipment downstream of the laminating site, as well as making bags adhere to one another after the cutting and stacking, packaging, etc., thereof, resulting in greater difficulty of product handling.
The exposed adhesive can also cause roll wraparounds, requiring temporary shutdown of the processing equipment to remove the wraparound, and rethreading of the roll. The exposed adhesive can also cause xe2x80x9csmall patch foldoversxe2x80x9d
However, it has been found that the above problems associated with the manufacture of the overhanging-patch bag (i.e., a xe2x80x9cfull-width patch bagxe2x80x9d) of the present invention can be adequately addressed by: (1) carefully selecting rolls of tubing having a lay-flat width narrow enough to ensure full patch coverage and overhang(s); (2) carefully monitoring patch skewing to ensure that an acceptably low level of skewing is present in the intermediate and final products; (3) increasing the frequency of cleaning of the laminator rolls and bagmaking rolls, to prevent excessive accumulation of adhesive which can cause product contamination; (4) careful handling of tubing rolls to prevent contamination of exposed glue surfaces; (5) careful monitoring of bags being produced, to ensure that small patch foldovers are not present, and removal of any products having such a defect; and (6) ensuring that the storage time of laminated rolls does not extend for so long that an unacceptable level of dirt accumulates on the exposed adhesive surfaces.